title: Helicopter emergency medical services (HEMS) over-triage and the financial implications for major trauma centres in NSW, Australia.
abstract: BACKGROUND
  In NSW Australia, a formal trauma system including the use of helicopter emergency medical services (HEMS) has existed for over 20 years. Despite providing many advantages in NSW, HEMS patients are frequently over-triaged; leading to financial implications for major trauma centres that receive HEMS patients. The aim of this study was to investigate the financial implications of HEMS over-triage from the perspective of major trauma centres in NSW.
  
  
  METHODS
  The study sample included all trauma patients transported via HEMS to 12 major trauma centres in NSW during the period: 1 July 2008 to 30 June 2009. Clinical data were gathered from individual hospital trauma registries and merged with financial information obtained from casemix units at respective hospitals. HEMS over-triage was estimated based on the local definition of minor to moderate trauma (ISS≤12) and hospital length of stay of less than 24 hrs. The actual treatment costs were determined and compared to state-wide peer group averages to obtain estimates of potential funding discrepancies.
  
  
  RESULTS
  A total of 707 patients transported by HEMS were identified, including 72% pre-hospital (PH; n=507) and 28% inter-hospital (IH; n=200) transports. Over-triage was estimated at 51% for PH patients and 29% for IH patients. Compared to PH patients, IH patients were more costly to treat on average (IH: $42,604; PH: $25,162), however PH patients were more costly overall ($12,329,618 [PH]; $8,265,152 [IH]). When comparing actual treatment costs to peer group averages we found potential funding discrepancies ranging between 4% and 32% across patient groups. Using a sensitivity analysis, the potential funding discrepancy increased with increasing levels of over-triage.
  
  
  CONCLUSIONS
  HEMS patients are frequently over-triaged in NSW, leading to funding implications for major trauma centres. In general, HEMS patient treatment costs are higher than the peer group average and the potential funding discrepancy varies by injury severity and the type of transport performed. Although severely injured HEMS patients are more costly to treat, HEMS patients with minor injuries make up the majority of HEMS transports and have larger relative potential funding discrepancies. Future episode funding models need to account for the variability of trauma patients and the proportion of patients transported via HEMS.
authors.affiliation: The George Institute for Global Health, Sydney, NSW, Australia. ctaylor@georgeinstitute.org.au
authors.forename: Colman B
authors.initials: CB
authors.lastname: Taylor
authors.forename: Kate
authors.initials: K
authors.lastname: Curtis
authors.forename: Stephen
authors.initials: S
authors.lastname: Jan
authors.forename: Mark
authors.initials: M
authors.lastname: Newcombe
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D017732:Air Ambulances / Q000191:economics*; D002648:Child; D016001:Confidence Intervals; D003365:Costs and Cost Analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009517:New South Wales; D012051:Reimbursement Mechanisms; D014193:Trauma Centers / Q000191:economics*; D014218:Triage / Q000191:economics*; D014947:Wounds and Injuries / Q000191:economics; D055815:Young Adult